Blue pencil (editing)

A blue pencil, also known as a checking pencil, is a two-color pencil traditionally used by an editor to correct a written copy.^[1] The blue end is typically Prussian blue, and the red end is typically a warm vermilion red.^[1][2] They are most often half red and half blue, but some are 70% red and 30% blue.^[3] An editor-in-chief would use a blue colored pencil to make proofreading marks and final notes on manuscripts before sending it to be typeset and published.^[4][5] The pencils and their blue excisions became associated with the editing process and editorial oversight.^[6][7]

Of course it takes skill to be a poet! But an editor? A pair of shears, a blue pencil, and a paste-pot!

— Alice Corbin Henderson^[8]

Since the introduction of desktop publishing, editing is typically done on computer files and without literal blue pencils.^[9][10][11] They continue to be used in the Japanese newspaper industry and elementary schools in parts of Europe.^[1][12] A different type of non-photo blue pencil is used by some comics artists for different purposes.^[13]